The AVMS (Around View Monitoring System) refers to a system that includes a plurality of cameras installed on a vehicle, recognizes an obstacle around the vehicle through an image taken by a camera, and estimates and warns of a collision risk with an obstacle located in a blind spot of a driver. Recently, the AVMS tends to be installed in expensive high-quality vehicles.
However, since a large vehicle such as a cargo truck, trailer or bus has a large full length, the large vehicle needs more cameras to apply the AVMS, and requires a more complex image recognition technique than general cars, in order to recognize images taken by the respective cameras. Such requirements make it difficult to apply the AVMS to a large vehicle. Therefore, while general cars have two side mirrors mounted thereon, more and more large vehicles include six side mirrors to widen a driver's monitoring range for a side rear blind spot.
FIG. 1 is a plan view illustrating that a large vehicle makes a turn at a crossroads. As illustrated in FIG. 1, when a bicycle 200 running in parallel to the large vehicle 100 is at the right rear of the large vehicle 100 while the large vehicle 100 tries to make a right turn, the bicycle 200 may not come in sight of a driver. Since the large vehicle 100 has a large full length, the bicycle 200 may come in contact with a side frame of the large vehicle 100, even though the bicycle 200 does not collide with a front wheel of the large vehicle 100. Then, the bicycle 200 may fall while losing the balance. In this case, while the rear wheel of the large vehicle 100 runs over a bicycle rider on a turn path of the large vehicle 100, the bicycle rider may die or receive a severe injury.
Such an accident does not frequently occur. However, when such an accident occurs, the accident is highly likely to cause a loss of life even though the large vehicle runs at low velocity. More specifically, when the large vehicle makes a turn along a walkway, a driver of the large vehicle may not recognize a bicycle, two-wheeled vehicle or pedestrian that has a smaller size and moves at lower velocity than the large vehicle, and thus cause an accident. In this case, as illustrated in FIG. 1, a danger zone 300 is formed in a triangular shape which is wide at the side front of the large vehicle and narrow at the side rear of the large vehicle. Since such an accident has a high death frequency, the accident needs to be prevented.
As illustrated in FIG. 2, the conventional large vehicle may include a short range radar (SRR) 110 mounted at the side front thereof, in order to monitor a moving object such as a bicycle 200 at the side rear thereof. Referring to FIG. 2, the SRR has a monitoring zone 120 of which the measurement angle is large while the measurement distance thereof is short. Thus, the SRR may widen the zone for monitoring the side rear of a passenger seat (or driver seat). However, when the moving object such as the bicycle 200 is located out of the monitoring zone 120 because the SRR does not cover the entire part of the danger zone 300 illustrated in FIG. 1, the driver cannot monitor the moving object. Furthermore, a large vehicle such as a trailer has a cargo bed made of a metallic material. Therefore, when the SRR is installed at the side rear of the vehicle, the SRR may have a difficulty in detecting a small bicycle due to propagation interference or the like.
Korean Patent Publication No. 2016-0045857 discloses a technique capable of detecting an object using a 3D camera and radar. However, the technique may have a difficulty in detecting a bicycle, two-wheeled vehicle or pedestrian in the turning radius of a large vehicle, even though the installation locations of the 3D camera and radar are differently applied and the object detection method is used. Therefore, the technique still has the above-described problems.